1. Field of the Invention
The present invention relates to a vibrating member and a manufacturing method of the member, and a vibration wave driving apparatus having the vibration member and a manufacturing method of the apparatus.
2. Related Background Art
Conventionally, as a vibration member used in an ultrasonic motor as a vibration wave driving apparatus, a circular- or track-shaped vibration member is known. Also, as is known in, e.g., U.S. Pat. No. 4,831,305, a plurality of projections are formed on such vibration member to magnify the vibration displacement.
The plurality of projections are formed by a cutting or grinding work, that requires much time and cost.
As a method of attaining a cost reduction of an ultrasonic motor, the present inventors proposed a method of manufacturing an elastic member, which constitutes the vibration member, by a press work.
An elastic member of a conventional ultrasonic motor is manufactured by a cutting or forging work. However, since the elastic member is manufactured from a plate material in the press work, it is impossible to obtain a conventional shape.
FIG. 11 is a perspective view showing a rotor and a vibration member of a circular-shaped ultrasonic motor manufactured by a known cutting or forging work.
A vibration member 1' is constituted by adhering a piezoelectric ceramic 1a' to a metal elastic member 1b' and a bottom surface portion 1d'. A rotor 2' has a contact portion 2a'.
As can be seen from FIG. 11, this shape is not suitable for a press work attained by bending a thin plate. Therefore, a cutting or forging work is required, resulting in high work cost.
With the press work using a thin plate as an inexpensive work method, a portion with poor bending rigidity is formed since the member is manufactured from the thin plate, and may disturb a function of the vibration member of the ultrasonic motor.